Heavy metals released from urban areas have toxic effects on aquatic organisms. Heavy metals in aquatic environments exist in various forms and methods designed to assess their effects need to consider their bioavailability. This study aimed to explore biomarkers in an estuarine amphipod, Grandidierella japonica, for exposure to heavy metals using metabolomics. We exposed G. japonica to different heavy metals and analyzed their metabolomes using high-resolution mass spectrometry.Partial least squares discriminant analysis (PLS-DA) was used to extract biomarkers of exposure for each heavy metal. As a result, three models were built to predict discrimination based on metabolomic profiles, and 70, 106, and 168 metabolites were extracted as biomarkers for exposure to Cu, Zn, and Cd, respectively. Our results suggest that PLS-DA was effective in extracting biomarkers, and this study demonstrated the usefulness of metabolomics as biomarkers.M. Yanagihara F. Nakajima (corresponding author) T. Tobino

Chronic toxicity tests provide information about effects on reproduction, but require considerable time and expense. In recent years, metabolomics has been used to predict the effects of contaminants on the reproductive output of organisms. The objective of this study was to predict toxic effects on the estuarine amphipod, Grandidierella japonica, using a model based on metabolic profiles. Metabolomes were extracted from surviving, laboratory-cultured G. japonica exposed to 25, 100, and 250 µg/L copper solution for 10 and 28 days. These metabolic profiles were obtained using an Orbitrap mass spectrometer (Orbitrap MS). Partial least squares regression models showed that metabolic profiles obtained after a 10-day exposure can predict the effect of copper on reproduction after a 28-day exposure. We demonstrated that metabolomic analyses of the estuarine amphipod G. japonica with Orbitrap MS can predict chronic toxicity effects.

Abstract. Urban farming is recently acknowledged as a strategy with various services in improving cities resilience but facing cons such as land competition and rapid urbanization. The study attempts to inventory available areas for urban farming implementation and estimate the total values with case study in Malang city, Indonesia. The study divided urban farming into five forms i.e. nursery, allotment, residential, institutional and rooftop farming based on its characteristics. Land inventory has been done by estimating existing and potential areas. Existing area was manually delineated by Field Area Measure App through field visit and visualized by ArcGIS. Potential area was identified through geospatial assessment considering land use and land cover map provided by the Government of Indonesia and parcel zoning based on Guideline of Urban Farming development and literatures. The study employed Contingent Valuation Method (CVM) and Market Price Method to estimate total values of urban farming. Currently there is 1.38 ha of urban farming which is equal to 0.01 % of city’s area distributed in 21 plots and 211.46 ha potential area or equal to 1.92 % of city’s area. Urban farming has services for amount of US$ 28.68 m−2 yr−1, specifically 22.86, 3.60, 0.80, 1.10 and 0.34 US$ m−2 yr−1 in terms of provisioning food; income generation; recreation and community building; education and learning; and maintenance urban comfort, respectively. If existing and potential area used for urban farming, then it could contribute to US$ 395,095.68 annually for existing and potentially up to US$ 60,646,800.35 annually for entire city.

Identifying substances in sediment that cause adverse effects on benthic organisms has been implemented as an effective source-control strategy. However, the identification of such

Control sediment in whole-sediment toxicity testing has a wide range of properties, but the effects of the sediment composition at the molecular level have not been investigated. Therefore, we adopted a metabolomic approach to assess the effects of sediment composition at the molecular level, in particular the effects of control sediment composition on the metabolomic responses of test species under control and test conditions. The estuarine amphipod Grandidierella japonica was incubated in test chambers with four types of sediment, and the metabolomes of G. japonica were analyzed using a high-resolution mass spectrometer. Metabolomes of G. japonica exposed to a copper (Cu) solution were also obtained in the same way. We found that the metabolomic profiles were affected by the composition of the control sediment and exposure to Cu and that the exposure to Cu caused a more dominant influence than the change in the compositions of control sediments. However, the metabolites that had key roles to discriminate between the control and Cu exposure groups differed between the tested control sediments. Our results suggest that the effects of control sediment are smaller than those of toxicant exposure, and toxicity assessment using metabolomics is possible regardless of the sediment type.